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71.
Fang Z Li T Wang Q Zhang X Peng H Fang W Hong Y Ge H Xiao Y 《Applied microbiology and biotechnology》2011,89(4):1103-1110
Laccases are blue multicopper oxidases with potential applications in environmental and industrial biotechnology. In this
study, a new bacterial laccase gene of 1.32 kb was obtained from a marine microbial metagenome of the South China Sea by using
a sequence screening strategy. The protein (named as Lac15) of 439 amino acids encoded by the gene contains three conserved
Cu2+-binding domains, but shares less than 40% of sequence identities with all of the bacterial multicopper oxidases characterized.
Lac15, recombinantly expressed in Escherichia coli, showed high activity towards syringaldazine at pH 6.5–9.0 with an optimum pH of 7.5 and with the highest activity occurring
at 45 °C. Lac15 was stable at pH ranging from 5.5 to 9.0 and at temperatures from 15 to 45 °C. Distinguished from fungal laccases,
the activity of Lac15 was enhanced twofold by chloride at concentrations lower than 700 mM, and kept the original level even
at 1,000 mM chloride. Furthermore, Lac15 showed an ability to decolorize several industrial dyes of reactive azo class under
alkalescent conditions. The properties of alkalescence-dependent activity, high chloride tolerance, and dye decolorization
ability make the new laccase Lac15 an alternative for specific industrial applications. 相似文献
72.
Development and characterization of wheat-Psathyrostachys huashanica partial amphiploids for resistance to stripe rust 总被引:1,自引:0,他引:1
Wang Y Xie Q Yu K Poysa V Lin L Kang H Fan X Sha L Zhang H Zhou Y 《Biotechnology letters》2011,33(6):1233-1238
Two partial amphiploid lines, B113 (32 plants) and B21 (13 plants), derived from a wheat-Psathyrostachys huashanica intergeneric cross were characterized by Giemsa C-banding and SDS-PAGE and evaluated for stripe rust resistance. All 15 partial
amphiploid plants were aneuploids with either 50 (8 plants), 51 (6 plants) or 54 (1 plant) chromosomes. Some showed regular
meiosis and all the P. huashanica chromosomes were included, although not in a single plant. Of 45 plants 34 showed specific bands on SDS-PAGE representing
high molecular weight glutenin subunit (HMW-GS) and 41 had bands representing P. huashanica low molecular weight glutenin subunit (LMW-GS), including two new subunits. All 45 plants were highly resistant (10) or immune
(35) to stripe rust mixed races CYR-30, CYR-31, Shuiyuan 7 and Shuiyuan 14. These amphiploid plants could be useful germplasm
for enhancing stripe rust resistance and might improve wheat grain quality. 相似文献
73.
Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100-4400 m in winter although the yearly home range spanned from 3500-4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use. 相似文献
74.
Characterization of a fungal strain capable of degrading chlorpyrifos and
its use in detoxification of the insecticide on vegetables 总被引:2,自引:0,他引:2
A fungal strain capable of utilizing chlorpyrifos as sole carbon and energy sources was isolated from soil by enrichment cultivation approach. The half-lives of degradation (DT50) for chlorpyrifos at concentrations of 1, 10, and 100 mg l−1 by the fungal strain DSP in mineral salt medium were measured to be 2.03, 2.93, and 3.49 days, respectively. Two cell-free extracts [E (1:10) and E (1:20)] from the fungal strain DSP in bran–glucose medium were prepared and used to enhance chlorpyrifos degradation on vegetables. Compared with the controls, the DT50 of chlorpyrifos were reduced by 70.3%, 65.6%, 80.6%, 80.6%, and 86.1%, and by 53.8%, 43.2%, 66.0%, 54.3%, and 67.7% on E (1:20) and E (1:10) treated pakchoi, water spinach, Malabar spinach, haricot beans, and pepper, respectively. The 7-day residual values (R
7) of chlorpyrifos on E (1:10) treated vegetables were all lower than the corresponding maximum residue levels of European Union (EU MRLs), except that the R
7 value on haricot beans was slightly higher than the corresponding EU MRLs. The results indicate that cell-free extracts could rapidly degrade chlorpyrifos residues on vegetables. 相似文献
75.
植物中参与活性氧调控的基因网络 总被引:4,自引:0,他引:4
植物体内活性氧(reactive oxygen species,ROS)是氧化还原反应的必然副产物,具极高的活性和毒性,从而对细胞产生毒害。同时,活性氧作为信号分子对很多生理过程诸如植物生长发育、细胞程序化死亡及生物和非生物胁迫应答起调控作用。植物中ROS双重作用的协调机制目前尚不明确,确定的是细胞中ROS维持于稳定水平需要精细的调节。拟南芥中至少包括152个基因组成的网络参与ROS的调控,该网络具高度的灵活性和互补性。本文综述了ROS网络中鉴定的一些关键基因及细胞学定位和协同作用,ROS信号转导,尤其是叶绿体中ROS信号的调控。 相似文献
76.
Chun-Lei Chen Xia-Fei Fu Lin-Qing Wang Jun-Jie Wang Hua-Gang Ma Shun-Feng Cheng Zhu-Mei Hou Jin-Mei Ma Guo-Bo Quan Wei Shen Lan Li 《Molecular biology reports》2014,41(3):1891-1899
Notch signaling pathway, a highly conserved cell signaling system, exists in most multicellular organisms. The objective of this study was to examine Notch signaling pathway in germ cell cyst breakdown and primordial follicle formation. The receptor and ligand genes of Notch pathway (Notch1, Notch2, Jagged1, Jagged2 and Hes1) were extremely down-regulated after newborn mouse ovaries were cultured then exposed to DAPT or L-685,458 in vitro (P < 0.01). Since DAPT or L-685,548 inhibits Notch signaling pathway, the expression of protein LHX8 and NOBOX was significantly reduced during the formation of the primordial follicles. Down-regulated mRNA expression of specific genes including Lhx8, Figla, Sohlh2 and Nobox, were also observed. The percentages of female germ cells in germ cell cysts and primordial follicles were counted after culture of newborn ovaries for 3 days in vitro. The result showed female germ cells in cysts was remarkably up-regulated while as the oocytes in primordial follicles was significantly down-regulated (P < 0.05). In conclusion, Notch signaling pathway may regulate the formation of primordial follicle in mice. 相似文献
77.
探讨我国森林野生动物红外相机监测规范 总被引:1,自引:0,他引:1
野生动物多样性是生物多样性监测与保护管理评价的关键指标, 因此对野生动物进行长期监测是中国森林生物多样性监测网络(CForBio)等大尺度生物多样性监测研究计划的一个重要组成部分。2011年以来, CForBio网络陆续在多个森林动态监测样地开展以红外相机来监测野生动物多样性。随着我国野生动物红外相机监测网络的初步形成, 亟待建立和执行基于红外相机技术的统一监测规范。基于3年来在我国森林动态监测样地红外相机监测的进展情况, 以及热带生态评价与监测网络针对陆生脊椎动物(兽类和鸟类)所提出的红外相机监测规范, 本文从监测规范和监测注意事项等方面探讨了我国森林野生动物红外相机监测的现状和未来。 相似文献
78.
Amano K Leung PS Rieger R Quan C Wang X Marik J Suen YF Kurth MJ Nantz MH Ansari AA Lam KS Zeniya M Matsuura E Coppel RL Gershwin ME 《Journal of immunology (Baltimore, Md. : 1950)》2005,174(9):5874-5883
Emerging evidence has suggested environmental factors as causative agents in the pathogenesis of primary biliary cirrhosis (PBC). We have hypothesized that in PBC the lipoyl domain of the immunodominant E2 component of pyruvate dehydrogenase (PDC-E2) is replaced by a chemical xenobiotic mimic, which is sufficient to break self-tolerance. To address this hypothesis, based upon our quantitative structure-activity relationship data, a total of 107 potential xenobiotic mimics were coupled to the lysine residue of the immunodominant 15 amino acid peptide of the PDC-E2 inner lipoyl domain and spotted on microarray slides. Sera from patients with PBC (n = 47), primary sclerosing cholangitis (n = 15), and healthy volunteers (n = 20) were assayed for Ig reactivity. PBC sera were subsequently absorbed with native lipoylated PDC-E2 peptide or a xenobiotically modified PDC-E2 peptide, and the remaining reactivity analyzed. Of the 107 xenobiotics, 33 had a significantly higher IgG reactivity against PBC sera compared with control sera. In addition, 9 of those 33 compounds were more reactive than the native lipoylated peptide. Following absorption, 8 of the 9 compounds demonstrated cross-reactivity with lipoic acid. One compound, 2-octynoic acid, was unique in both its quantitative structure-activity relationship analysis and reactivity. PBC patient sera demonstrated high Ig reactivity against 2-octynoic acid-PDC-E2 peptide. Not only does 2-octynoic acid have the potential to modify PDC-E2 in vivo but importantly it was/is widely used in the environment including perfumes, lipstick, and many common food flavorings. 相似文献
79.
80.
Yingnan Zhang Charles Eigenbrot Lijuan Zhou Steven Shia Wei Li Clifford Quan Jeffrey Tom Paul Moran Paola Di Lello Nicholas J. Skelton Monica Kong-Beltran Andrew Peterson Daniel Kirchhofer 《The Journal of biological chemistry》2014,289(2):942-955
PCSK9 (proprotein convertase subtilisin/kexin type 9) is a negative regulator of the hepatic LDL receptor, and clinical studies with PCSK9-inhibiting antibodies have demonstrated strong LDL-c-lowering effects. Here we screened phage-displayed peptide libraries and identified the 13-amino acid linear peptide Pep2-8 as the smallest PCSK9 inhibitor with a clearly defined mechanism of inhibition that has been described. Pep2-8 bound to PCSK9 with a KD of 0.7 μm but did not bind to other proprotein convertases. It fully restored LDL receptor surface levels and LDL particle uptake in PCSK9-treated HepG2 cells. The crystal structure of Pep2-8 bound to C-terminally truncated PCSK9 at 1.85 Å resolution showed that the peptide adopted a strand-turn-helix conformation, which is remarkably similar to its solution structure determined by NMR. Consistent with the functional binding site identified by an Ala scan of PCSK9, the structural Pep2-8 contact region of about 400 Å2 largely overlapped with that contacted by the EGF(A) domain of the LDL receptor, suggesting a competitive inhibition mechanism. Consistent with this, Pep2-8 inhibited LDL receptor and EGF(A) domain binding to PCSK9 with IC50 values of 0.8 and 0.4 μm, respectively. Remarkably, Pep2-8 mimicked secondary structural elements of the EGF(A) domain that interact with PCSK9, notably the β-strand and a discontinuous short α-helix, and it engaged in the same β-sheet hydrogen bonds as EGF(A) does. Although Pep2-8 itself may not be amenable to therapeutic applications, this study demonstrates the feasibility of developing peptidic inhibitors to functionally relevant sites on PCSK9. 相似文献